John Frank Strong was 39 years old when John F. Kennedy was assassinated by Lee Harvey Oswald in Dallas, Texas; hours later, Lyndon B. Johnson was sworn in aboard Air Force One as the 36th President of the United States. John Fitzgerald Kennedy, commonly referred to by his initials JFK, was an American politician who served as the 35th President of the United States from January 1961 until his assassination in November 1963. He served at the height of the Cold War, and the majority of his presidency dealt with managing relations with the Soviet Union. As a member of the Democratic Party, Kennedy represented the state of Massachusetts in the United States House of Representatives and the U.S. Senate prior to becoming president.